The invention relates to a food, and more particularly to a moist pet food comprising a mixture of a high moisture, vitamin- and mineral-fortified nutritional gravy and retort stable blood based chunks suitable for use as a top dressing for a dry pet food or to use along as a nutritional pet food.
Within the class of foods known as pet foods, there are three basic subdivisions, dry pet food, semi-moist pet food, and moist pet food. The moisture is determined by considering both the water present in the final product and the water combined with the various components that make up the final product. In general, the dry pet food--due to its low moisture content which is usually less than about 15 percent--tends to exhibit the greatest microbiological stability and requires no special handling or packaging after processing.
At the opposite end of the spectrum is the moist pet food having a moisture content in excess of about 50 percent. Due to the high moisture content of the moist pet food, microbiological stability is a major problem. This problem in a moist pet food is overcome only by heat sterilizing the moist pet food and packaging the moist pet food in a hermetically sealed container. Even with the heat sterilization and hermetically sealed package, refrigeration is required after the package of moist pet food is opened to preserve the leftover pet food for even a short time.
Semi-moist pet food has a moisture content generally ranging from about 15 percent to about 50 percent. Since semi-moist pet foods are higher in moisture content than dry and lower in moisture than canned, special techniques are required to render it microbiologically stable. This moisture content in combination with special techniques may produce a microbiologically stable food which does not require refrigeration. At the same time, the higher moisture content of the semi-moist pet food provides an increased palatability when compared to the dry pet food. The semi-moist pet food is generally rendered microbiologically stable by using high levels of sugar and solutes.
A typical formula of a dry pet food will show from 24 to 50 percent starch and/or starch-like materials; between 10 to 30 percent vegetable protein; 5 to 25 percent animal protein; 5 to 15 percent fat material; and 1 to 7 percent supplemental ingredients like vitamins, minerals, flavoring, coloring, antioxidants and other ingredients plus up to 15 percent moisture.
A dry pet food with its 10 percent moisture content is the most stable pet food and requires the least sophisticated processing and packaging techniques for stabilization. Dry pet foods typically have a hard, brittle, shell structure. While they can be highly nutritious, they also may not be nutritious and thus need a dressing (or an additive) to add essential vitamins and minerals. The dry pet foods also lack palatability. Such products are fed on an "as is" self-feeding basis in some kennels or are moistened with additives or dressings such as water, soups, gravies, or even moist all meat canned foods to increase palatability and consumption. Except for water, these additives are somewhat effective and may or may not be nutritional. A high moisture gravy, which is fortified with vitamins and minerals can further enhance nutrition and plalatability of a dry dog food if used as a top dressing. Additional improvements in texture, appearance, palatability and nourishment can result in the fortified gravy component if it is blended with retort stable meat-like pieces made predominantly from blood.
Blood contributes a high percentage of protein, and supplements the color, odor, flavor and nutrients of a canned pet food. It is a possible additive to gravy to form a moist pet food for use with other pet foods. However, when high levels (above 5%) of citrated or liquid blood are used, the moist pet food becomes a food with a dark, unappetizing color with a corresponding effect on odor and flavor. Furthermore, blood does not form stable meat-like chunks when simply added to a gravy and then retorted.
Thus, these detrimental features permit no high percentage usage of blood in commercial moist pet foods. Yet, blood is a readily available material. Due to this availability, it is an economical source of protein in ample supply. It is also palatable and has very little fat. If a means can be found for using greater quantities of blood in commercial moist pet foods, the advantages of blood can be put to their best use.
Even when sodium citrate or citric acid is added to fresh blood to prevent its coagulation, or blood is nitrated to hold its color, neither of these additions affects the protein content of blood. Blood averages about 17.6% protein and 81% water. This nutrient level compares very favorably with other meat or meat by-products used in pet food formulations. For example, the following ingredients show the following percentage of protein:
Pork lungs: 12.9% Protein Average;
Beef hearts: 13.6% Protein Average;
Beef spleens: 17.1% Protein Average;
Beef gullets: 12.5% Protein Average on an as is basis.
One variety of a moist pet food is the canned chunk and gravy type. This product may be used as a total diet for pets or used as a supplement for a pet's daily ration. Generally, the chunks in such a product are pieces of meat or formed pieces of a mixture of meat and cereal. Such canned products supply aroma, palatability and some added nutritional properties. The gravy portion usually has a fluid characteristic, and may be quite low in a number of essential nutrients for a pet's health. If a gravy with sufficient nutrients can be mixed with retort stable chunks made predominantly of blood, a nutritional improvement in the pet's diet can result. However for reasons described above, it is difficult to provide a meat-like chunk using only blood for use with a gravy to form a top dressing or to form a nutritious pet food alone.